Vacuum cleaner

ABSTRACT

A vacuum cleaner includes a housing, a carriage disposed on the housing with a plurality of wheels, and a suction opening. A suction connector is rotatably disposed at the suction opening. The suction connector is connected to an end portion of a suction hose associated with the vacuum cleaner housing. At least one of the suction opening and the suction connector is configured to enable an additional movement of the suction connector relative to the rotatable movement of the suction connector. At least one transducer is activatable by the additional movement and configured to generate electrical control signals. A control unit is configured to receive the control signals and control at least one of the plurality of wheels with a converted signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a U.S. National Phase application under 35 U.S.C. §371 of International Application No. PCT/EP2007/000943, filed on Feb. 5, 2007, and claims the benefit of German Patent Application No. 10 2006 008 556.6, filed on Feb. 22, 2006. The International Application was published in German on Aug. 30, 2007 as WO 2007/096048 A1 under PCT Article 221(2).

FIELD

The present invention relates to a vacuum cleaner including a carriage which is provided with wheels and is mounted to the vacuum cleaner housing, and further including a suction opening to accommodate at least one suction connector which is at least rotatable and is connected to the end portion of a suction hose which end portion is associated with the vacuum cleaner housing.

BACKGROUND

A so-called “canister vacuum cleaner” for domestic use may be used, for example, to clean floor surfaces. The carriage of canister vacuum cleaners usually includes three wheels, of which two are mounted on an axle such that they are freely rotatable. During the cleaning operation, the person using the vacuum cleaner pulls the vacuum cleaner behind him/her, causing it to follow him/her. For this purpose, the carriage is further provided with a caster which is rotatable about a vertical axis. Pulling of the vacuum cleaner is effected by stretching the hose, thereby exerting a pulling force on the vacuum cleaner.

The above-described vacuum cleaner has proved to be very useful. However, it can be perceived to be disadvantageous that the person using the vacuum cleaner must cause the vacuum cleaner to follow him/her if he/she wishes to prevent stretching of the hose.

SUMMARY

An aspect of the present invention is to provide a canister vacuum cleaner that automatically follows the user, thereby providing increased ease-of-use.

In an embodiment, the present invention provides a vacuum cleaner including a housing, a carriage disposed on the housing with a plurality of wheels, and a suction opening. A suction connector is rotatably disposed at the suction opening. The suction connector is connected to an end portion of a suction hose associated with the vacuum cleaner housing. At least one of the suction opening and the suction connector is configured to enable an additional movement of the suction connector relative to the rotatable movement of the suction connector. At least one transducer is activatable by the additional movement and configured to generate electrical control signals. A control unit is configured to receive the control signals and control at least one of the plurality of wheels with a converted signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained in greater detail below with reference to the drawings, in which:

FIG. 1 is a view showing a vacuum cleaner of the present invention embodied in the form of a canister vacuum cleaner;

FIG. 2 is an exploded view illustrating the connection between the suction connector and the suction opening;

FIG. 3 is a purely schematic view of the spherical bearing receiving the suction connector;

FIG. 4 is an elevation showing the spherical bearing and the end position detection unit;

FIG. 5 is a top view corresponding to the view shown in FIG. 4;

FIG. 6 is a purely schematic view showing the vacuum cleaner of FIG. 1 along with the end position detection unit and the control unit; and

FIG. 7 is a block diagram showing the sensor unit for controlling the drive motors.

DETAILED DESCRIPTION

In an embodiment, the suction opening for attachment of the suction connector and/or the suction connector is/are configured such that the suction connector can additionally be moved relative to the rotational movement thereof, and that at least one transducer is provided which is activatable by the additional relative movement and used to generate electrical control signals which can be fed to a control unit, and that certain wheels of the carriage can be controlled in their direction of travel by signals converted by the control unit.

The suction connector is connected and supported within the suction opening in such a way that the suction connector is movable in three dimensions, i.e., it is rotatable in opposite directions and can additionally perform a further movement. This further movement is then used to activate the transducer to produce signals which are then suitably converted into control signals for the motors driving the wheels. Since the carriage now has individually drivable wheels, either all or only one of the drive motors are energized in response to the activation of the transducer, or the drive motors are driven at different speeds, causing the vacuum cleaner to move automatically either in a straight line or along a curved path. Thus, when the transducer is activated, it will not only generate ON and OFF signals, but also directional signals. In accordance with this embodiment of the present invention, the suction hose and the suction connector together form a mechanical transducer. When, during vacuuming, the maximum reach of the suction hose has been reached because of its fixed length, the hose becomes stretched, and the generated pulling force is transmitted to the suction connector. This pulling force then causes the additional movement relative to the possible rotational movement. Consequently, this results in a distribution of forces within the bearing for the suction connector.

In an embodiment, the bearing for the suction connector is provided within the suction opening in the form of a spherical bearing. This enables the suction connector to perform a tilting movement in addition to the rotational movement in opposite directions. The suction connector is able to perform such tilting movement in any position within the range of rotation.

A simple construction is obtained if the spherical bearing includes a sleeve which is mounted in the suction opening to receive the suction connector. This sleeve can then be rotated within the suction opening and, at the same time, is able to perform the additional tilting movement. This capability of movement of the sleeve can be achieved in a very simple way if the outer contour of the sleeve is ball-like in shape, shaped as a spherical segment or the like, and if the suction opening is adapted to the outer contour of the sleeve, and if the fit between the sleeve and the suction opening is a clearance fit.

The resulting play, i.e. the oversize of the suction opening in relation to the outer contour of the sleeve, enables the sleeve to move very freely within the suction opening. Therefore, only a very small pulling force is needed to cause the movement for activating the transducer. Moreover, the amount of play provided by the clearance fit is selected such that the fit can still be regarded as being free from play, thereby preventing rattling or similar noises.

Moreover, the sleeve has a plurality of angularly spaced groove-like recesses formed in the outer surface thereof, said recesses extending in the direction of the axis of rotation of the sleeve. This enables the suction connector to automatically spring back within its bearing when the pulling forces exerted by the suction hose have ceased. Therefore, there is no need for any additional spring elements to provide the restoring force. In a preferred embodiment, four recesses are provided in the outer surface of the sleeve such that they are offset from each other by 90 degrees.

To enable the signals that are fed from the transducer to the control unit to be appropriately converted, i.e., to be converted into switching signals for the drive motors and into additional directional signals, a flange is provided on the end of the sleeve facing the suction connector, and a plurality of limit switches are mounted at spaced apart positions in the vacuum cleaner housing, forming an end position detection unit. This end position detection unit may be of electromechanical or electronic design. Depending on which limit switch is actuated in response to a pulling force acting on the suction connector, the control unit will activate the circuits of the drive motors accordingly. The limit switches are disposed on a circular arc concentric with the axis of rotation of the sleeve.

In order to trigger the signals determining the direction of the vacuum cleaner, it is proposed that at least two light barriers which operate using the reflection method be associated with the spherical bearing. These light barriers operate according to the general optical principle, it being proposed that each light barrier that works as an emitter be disposed on the outside of the sleeve, and that the receiver be disposed in the suction opening of the vacuum cleaner housing, which forms the outer bearing. This configuration of the sleeve and of the outer bearing in the form of the suction opening, in conjunction with the suction connector, also isolates the system from the dirt-laden air.

In a further embodiment, the end position detection unit is designed to operate in either digital or analog mode. The transmission of the activation and directional signals can be accomplished in different ways. It is proposed for these signals to be transmittable through wires or cables, or wirelessly, for example, by means of radio signals, infrared signals, or similar signals. Wireless transmission has the advantage of eliminating the need for suitable electrical wires.

In an embodiment of the vacuum cleaner of the present invention, the suction connector, the sleeve mounted in the suction opening, and the end position detection unit together form a sensor unit for controlling the drive motors of the wheels or rollers.

Moreover, the control circuit of the control unit can include control electronics containing a microcontroller, and that the control circuit further include a number of circuit breakers equivalent to the number of drive motors. In one embodiment two wheels that are mounted on a common axle are driven. Each of the wheels is also mounted such that it is freely rotatable, so that the vacuum cleaner can be pulled manually. Each drive motor has one circuit breaker associated therewith. When the microcontroller detects the activation and directional information, it activates the drive motors by means of the circuit breakers. If the two drive motors are supplied with voltages of different magnitudes, the vacuum cleaner will make a turn, i.e., move along a curved path. If the voltages are the same, the path of travel remains a straight line.

The vacuum cleaner 1 shown in FIG. 1 is designed as a canister vacuum cleaner which is provided with a carriage including two rear wheels 3 which are mounted at the sides of housing 2 on an axle and a front caster 4 (see FIG. 6). Mounted in housing 2 are the functional components of the vacuum cleaner. A dust chamber cover 6 is secured to housing 2 such that it is pivotable about an axis parallel to the axle of wheels 3. In FIG. 1, dust chamber cover 6 is shown in its open position. Dust chamber cover 6 is provided with a suction opening 7 (FIG. 2), in which a suction connector 8 is rotatably and tiltably supported in a manner which will be described in greater detail hereinafter. Attached to suction connector 8 is an extensible suction hose 9, whose other end leads to a telescoping suction wand 10. The connecting portion between telescoping suction wand 10 and suction hose 9 is configured as a handle 11. A suction brush 12 is attached to the free end of telescoping suction wand 10.

FIG. 2 shows that the end of suction connector 8 that faces housing 2 is insertable into suction opening 7. This connection region is configured such that the suction connector can be arbitrarily rotated in the plane of the cover, and that it can additionally perform a tilting movement in a manner which will be described in greater detail hereinafter. As will be explained later, suction connector 8 is supported in suction opening 7 by a bearing which is designed in the manner of a spherical bearing. When in the connected state, suction connector 8 is locked within suction opening 7. This locking engagement can be released in order to remove suction connector 8.

FIG. 3 shows a portion of dust chamber cover 6. It can be seen that suction opening 7 is ball-like in shape; i.e., the inner diameter increases continuously from the ends toward the center. FIG. 3 further shows a sleeve 14 which can be mounted in suction opening 7 and whose outer contour is adapted to the spherical contour of suction opening 7. The bore is cylindrical so that the proximal end of suction connector 8 can be sealingly inserted therein. Moreover, sleeve 14 has a flange 15 formed on its end facing suction connector 8. The outer dimensions of sleeve 14 are matched to the inner dimensions of suction opening 7 in such a way that a clearance fit is provided. This enables sleeve 14 to move freely within suction opening 7. This movement of sleeve 14 is caused by a pulling force exerted by suction hose 9 when the person using the vacuum cleaner has moved so far away from vacuum cleaner 1 that said pulling force acts on suction hose 9. In order for sleeve 14 to always spring back to its original position, four recesses 16 are provided in the outer surface of sleeve 14 such that they are offset from each other by 90 degrees and extend in the direction of the axis of rotation of sleeve 14.

FIGS. 4 and 5 illustrate the arrangement of three electromechanical limit switches 17, 18, 19 which are fixedly mounted in dust chamber cover 6 and which together form a transducer or end position detection unit. The plungers of these limit switches 17, 18, 19 are denoted by reference numerals 17′, 18′ and 19′. As shown in FIG. 4, plungers 17′, 18′ and 19′ are in contact with the lower surface of flange 15. Moreover, FIG. 5 shows that the plungers are disposed on a circular arc concentric with the axis of rotation of suction connector 8. In the position shown in FIG. 4, no pulling force is exerted by suction hose 9 on sleeve 14, plungers 17′, 18′ and 19′ are in an extended position, and no control signal is generated. FIG. 5 indicates that sleeve 14 is able to rotate, while FIG. 4 shows that it can additionally perform a tilting movement. Depending on the direction of the tilting movement, at least one limit switch 17, 18, 19 will be actuated. This signal or these signals is/are fed to control unit 20 and converted therein into ON and OFF signals for motors M1 and M2 for driving the wheels 3 of vacuum cleaner 1. In addition, control unit 20 is able to identify from which limit switch 17, 18, 19 the signals were transmitted, so as to additionally generate at least one directional signal causing vacuum cleaner 1 to move along a curve or bend.

FIG. 7 shows a block diagram illustrating the control circuit of the motors M1 and M2 driving the wheels 3. As shown therein, the sensor unit is formed by suction connector 8, suction hose 9, and sleeve 14. The signals generated by limit switches 17, 18, 19 are fed to control unit 20. Control unit 20 is also coupled to the power supply of vacuum cleaner 1, as is indicated by the two poles (+) and (−). The control electronics of the vacuum cleaner includes a microcontroller 21 and two circuit breakers 22, 23 in order to transmit suitable control signals to motors M1 and M2. In the exemplary embodiment shown, these control signals are transmitted through wires. Unlike the embodiment shown, the transmission could also be wireless, for example, via radio or infrared signals. As shown in FIG. 7, the two motors M1, M2 can be activated simultaneously, but it is also possible to activate only one motor. Furthermore, the operating voltages could be varied to cause vacuum cleaner 1 to move along a curve or bend.

The present invention is not limited to the exemplary embodiment shown herein. The illustrated embodiment demonstrates that suction hose 9 and suction connector 8 are used together to function as a mechanical transducer which, in conjunction with the end position detection units or limit switches 17, 18, 19, transmits control signals to a control unit 20, said control signals being processed in said control unit and used to control the motors M1, M2 driving the wheels 3. 

1-15. (canceled)
 16. A vacuum cleaner comprising: a housing; a carriage disposed on the housing including a plurality of wheels; a suction opening; a suction connector rotatably disposed at the suction opening, the suction connector being connected to an end portion of a suction hose associated with the vacuum cleaner housing, at least one of the suction opening and the suction connector being configured to enable an additional movement of the suction connector relative to a rotatable movement of the suction connector; at least one transducer activatable by the additional movement and configured to generate electrical control signals; and a control unit configured to receive the control signals and control at least one of the plurality of wheels with a converted signal.
 17. The vacuum cleaner as recited in claim 16 wherein the plurality of wheels include two wheels, and further comprising drive motors coupled to the two wheels and configured to drive the wheels.
 18. The vacuum cleaner as recited in claim 16 wherein the suction connector includes a spherical bearing disposed in the suction opening.
 19. The vacuum cleaner as recited in claim 18 wherein the spherical bearing includes a sleeve disposed in the suction opening.
 20. The vacuum cleaner as recited in claim 19 wherein an outer contour of the sleeve has a ball-like shape, the suction opening is adapted to the outer contour, and the sleeve and suction opening have a clearance fit therebetween.
 21. The vacuum cleaner as recited in claim 19 wherein an outer contour of the sleeve includes a spherically shaped segment, the suction opening is adapted to the outer contour, and the sleeve and suction opening have a clearance fit therebetween.
 22. The vacuum cleaner as recited in claim 19 wherein an outer surface of the sleeve includes a plurality of angularly spaced recesses, each recess extending in a direction of an axis of rotation of the sleeve.
 23. The vacuum cleaner as recited in claim 23 wherein the recesses are in the shape of a groove.
 24. The vacuum cleaner as recited in claim 21 wherein the plurality of recesses includes four recesses offset from each other by 90 degrees.
 25. The vacuum cleaner as recited in claim 19 wherein an end of the sleeve includes a flange facing the suction connector, and further comprising a plurality of limit switches disposed in the housing at spaced apart positions so as to form an end position detection unit.
 26. The vacuum cleaner as recited in claim 25 wherein the limit switches include at least one of electromechanical and electronic switches, and wherein the limit switches are disposed on a circular arc that is concentric with an axis of rotation of the sleeve.
 27. The vacuum cleaner as recited in claim 25 further comprising at least two light barriers each operating as an emitter using a reflection method and disposed on an outside of the sleeve, and further comprising a respective receiver disposed in the suction opening, wherein the light barriers are configured to trigger signals for determining the direction of the vacuum cleaner.
 28. The vacuum cleaner as recited in claim 25 wherein the end position detection unit is configured to operate in a digital or analog mode.
 29. The vacuum cleaner as recited in claim 25 wherein the control signals are transmittable through wires.
 30. The vacuum cleaner as recited in claim 25 wherein control signals are wirelessly transmittable.
 31. The vacuum cleaner as recited in claim 30 wherein the control signals include at least one of radio signals and infrared signals.
 32. The vacuum cleaner as recited in claim 19 wherein the suction hose, the suction connector and the sleeve collectively form a sensor unit.
 33. The vacuum cleaner as recited in claim 16 wherein the transducer includes a plurality of limit switches forming an end position detection unit
 34. The vacuum cleaner as recited in claim 17 wherein a control circuit of the control unit includes control electronics including a microcontroller and a number of circuit breakers equal to a number of the drive motors.
 35. The vacuum cleaner as recited in claim 16 wherein the transducer is disposed on the housing. 